A mechanistic model for stochastic rebound of solid particles with application to erosion predictions

Abstract

Erosive wear due to solid particle impacts is a significant challenge in process industries, especially for oil and gas industries where multiphase flow with the presence of solid particles conveyed by the fluid is very common. Solid particle erosion is a complex phenomenon with multiple factors contributing to its severity. Based on available studies in the literature, mechanistic and empirical erosion models are available that are being used by investigators to predict erosion in complex geometries. The erosion models require particle impact speed and angle to be determined for predicting solid particle erosion. Thus, in many applications, Computational Fluid Dynamics (CFD) codes are used to track the trajectories of solid particles to model erosion in complex geometries. However, the problem of predicting erosion in complex geometries where rebounded particles can have a significant effect on erosion pattern has been addressed only by a few investigators in the literature. The complexity results from the fact that trajectories of rebounded particles and their resulting velocities must be determined. The current investigation uses experimental data and modelling to determine the effects of particle rebounds on erosion patterns. The experimental setup is composed of two stainless steel and aluminum specimens at a right angle to each other, and the angle between the nozzle and first specimen is 45 degrees. The second specimen is painted to determine the erosion pattern caused by rebounding particles from the first. The effects of material composition and surface roughness on the rebounding particles are presented. Additionally, a mechanistic rebound model describing the erosion pattern, erosion intensity and location of maximum erosion is presented, and the predictions are compared with experimental data. It is found that the rebound model has a great influence on erosion prediction especially where subsequent particle impacts are expected. It is also shown that the existing empirical rebound correlations in the literature are not effective for erosion calculation purposes.